Runners gather at the start line for the annual “Santa Speedo Run”, a charity race through the streets of the Back Bay neighborhood of Boston. (Photo by Gretchen Ertl/Reuters)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

An airplane house is pictured in the village of Miziara, northern Lebanon May 12, 2015. Miziara prides itself on building residential homes that resemble ancient Greek temples and Egyptian ruins, one is even built in the shape of an Airbus A380. (Photo by Aziz Taher/Reuters)

The first red panda cub was born on May 30 in zoo Zlin. Zoologist Roman Vrzal holds a male of red panda. The Red panda is pictured in Zlin, Czech Republic, August 20, 2014. (Photo by Dalibor Gluck/CTK)

Kumari Samita Bajracharya sits in front of devotees offers during a special puja at Kumari Ghar in Patan, Nepal, 09 April 2011. It is believed that worshipping Kumari and receiving tika from her reduces illness and avoid problems. Kumari, or Kumari Devi, is a “living goddess”. The word literally means virgin in Nepali. The Living Goddesses are young pre-pubescent girls that are considered to be incarnations of the Hindu Goddess of Power, Kali. The Kumari retires when she reaches puberty. (Photo by Narendra Shrestha/EPA)

A group of 1000 customers receive a facial massage at a sports centre in Jinan, Shandong province, China, May 4, 2015. A group of 1000 women were given a 30 minutes facial beauty treatment together on Monday that achieved a Guinness record for the largest group of people having beauty treatment in the same location, according to local media. (Photo by Reuters/Stringer)

A vendor (C) cuts slaughtered dogs for sale at his roadside stall in Duong Noi village, outside Hanoi December 16, 2011. While animal rights activists have condemned eating dog meat as cruel treatment of the animals, it is still an accepted popular delicacy for some Vietnamese, as well in some other Asian countries. Duong Noi is well-known as a dog-meat village, where hundreds of dogs are killed each day for sale as popular traditional food. Dog-eating as a custom is rooted in Vietnam and was developed as a result of poverty. One kilogram of dog meat costs about 130,000 dongs ($6.2). (Photo by Reuters/Kham)

Actress Penelope Cruz attends a photocall promoting the film “Chromophobia” at the Palais during the 58th International Cannes Film Festival May 21, 2005 in Cannes, France. (Photo by M. J. Kim/Getty Images)